Break of the bottom of the stilk. Feel your way up from the bottom until the stilk breaks off easily. That way you are able to remove the less tender part of the asparagus.
If the skin is very thick you can peel it off.
Place the asparagus in boiling salted water for 5-7 minutes. Check them regularly as they should still have some resistance, or be a little bit "al dente".
The Hollandaise sauce
Cut the shallot onion in small pieces.
Add shallots, white wine, thyme, bay leaf and pepper into a sauce pan.
Let the mixture simmer slowly until allmost dry (aprox 2 tbs of juice should be left). The longer it takes to reduce the mixture, the more taste will be left in the reduction so it is important not to boil this too strongly.
Filter the mixture to keep only the juice.
Clarify the butter, by first melting it without stirring. remove the "milk" that appears on the top with a spoon, and slowly poor the butter into a small sauce pan leaving the white solid part of the butter behind. Keep this butter warm (but not boiling).
Add the egg yolks into the wine/shallot reduction and whisk vigoursly over medium/low heat. The mixture should become thick and airy and you can stop when you start to see the bottom of the sauce pan when you whisk. It is important that the heat is not too high while doing this as the eggs may coagolate. Touch the sides on your sauce pan regularly to check that it is warm, but not hot. Add salt at this stage (aprox 1/2 tsp)
Remove the pan from the heat and place it on a kitchen cloth (to keep it stable). Keep whisking vigourously while very slowly adding the clarified butter. Start by adding a few drops of butter at the time and gradually whisk in more and more. Taste if you need more salt.
Add a good squize of lemon in the end. The sauce is supposed to be thick but if you find it too thick you can add a little bit of water.
Serving
Place the asparagus nicely on a plate and pour the sauce on top. Sprinkel with parmesan and/or aything else you have that can give some extra peps (truffel, bacon...)
Notes
This sauce cannot be reheated and it should never boil. It is best prepared just before serving.